The invention concerns a process for open-end friction spinning where the fibers are fed on the casing surface of a friction roller (designed as a suction roller) and where the fibers are conveyed onto the casing surface to a spinning wedge in which they are twisted together into a yarn, and a device for carrying out the process.
While yarn spun with a friction spinning device can be made at high production speeds, the yarn quality still remains unsatisfactory. This is caused by insufficient drawing of the fibers into the fiber joint. It has been proposed in German Patent No. DE-OS 2,943,063 to feed the fibers at an angle to the draw-off direction of the yarn, where the air stream flows in such manner in the vicinity of the yarn forming surface as to cause at least a portion of the fibers to be redirected as they approach the yarn forming surface, their new direction being more closely parallel to the axis of the drawn-off yarn. It was found, however, that the problem of yarn quality could not be solved by means of this device.
In another known open-end friction spinning device, the untwisted fibers are fed by a fiber feeding channel, installed at a distance from the wedge-shaped wedge of a suction roller, so that the fibers are subjected to a change of direction at the edge of the feeding channel outlet before they reach the wedge German Patent No. DE-OS 3,300,636. This change of direction is intended to cause drafting or drawing of the fibers. However, this measure, also, does not yield the expected results.